At the scene of an accident, a police officer notices that the skid marks of a car re 10 m long. The officer knows that the typical deceleration of this car when skidding is -45 m/s^2. What can the officer estimate for the original speed of the car?

the moving of the box is a result of centripetal force. think of that  as a car or a truck in this case creates a turn, the force of friction performing upon the turned wheels of the car runs centripetal force obligatory for circular motion for the things inside it.